My math teacher gave us this puzzle with the promise of "something special" if we figured it out. I've tried, but I just cant figure it out and its giving me a headache! Anyone that can help me would be greatly appreciated.

The Puzzle:

"A Mathematician was early on his way to work one day and decided to figure out how many possible ways he could get to work. Help the mathematician figure out how many possible routes there are from START to FINISH.

__You may only move to the right and cannot go backwards. If you reach a fork, you can take the top or bottom path.__
Thanks in advance to anyone who can help